diff --git a/.azure-pipelines/linux.yml b/.azure-pipelines/linux.yml
index 6965a15fc..e55980743 100644
--- a/.azure-pipelines/linux.yml
+++ b/.azure-pipelines/linux.yml
@@ -1,3 +1,6 @@
+variables:
+  CI: true
+
 jobs:
 - template: jobs/test.yml
   parameters:
diff --git a/.azure-pipelines/macos.yml b/.azure-pipelines/macos.yml
index 85c2a0246..9ad9edae8 100644
--- a/.azure-pipelines/macos.yml
+++ b/.azure-pipelines/macos.yml
@@ -1,3 +1,6 @@
+variables:
+  CI: true
+
 jobs:
 - template: jobs/test.yml
   parameters:
diff --git a/.azure-pipelines/windows.yml b/.azure-pipelines/windows.yml
index 9d1bf5385..f56b8f504 100644
--- a/.azure-pipelines/windows.yml
+++ b/.azure-pipelines/windows.yml
@@ -1,3 +1,6 @@
+variables:
+  CI: true
+
 jobs:
 - template: jobs/test-windows.yml
   parameters: